Introduction –

Network latency and Bandwidth are the two metrics most likely to be of interest when you benchmark a network. Even though most service and product advertising focuses on bandwidth, at times the latency can be a more important metric.

** What is Bandwidth?

Bandwidth (BW) in computer networking refers to the data rate supported by a network connection or interface. BW is measured in terms of bits per second (bps).

** What is Network latency?

Latency is a measure of time delay experienced in a system. Network latency is simply defined as the time delay observed as data transmits from one point to another. There are a number of factors that contribute to network latency. These include transmission(medium of connectivity), Distance, Routers and computer hardware delays.

List of Projects used to test Network performance and Bandwidth –

1) bmon – Bandwidth monitor and rate estimator, it is console based,live BW
2) bwbar – Bandwidth usage in Text and Graphical format
3) bwm-ng – Bandwidth Monitor NG (Next Generation, live BW, console based
4) dstat – Dstat is a replacement for vmstat, iostat and ifstat.
5) iftop – Bandwidth usage on an interface, console based
6) iperf – Perform Network throughput tests bet two host
7) ifstat – Report InterFace STATistics
8) cbm – Color Bandwidth Meter ,console based
9) etherape – Graphical network traffic browser
10) iptraf – Interactive Colorful IP LAN Monitor, console and GUI based
11) netmrg – It is daemon based, mySQL support, Gathers data from devices.
12) nuttcp – Network performance measurement tool
13) nepim – network performance

NOTE ~ For some of them rpm or deb packages are not available!

Step 1] How to install on Redhat/RHCE,CentOS based system and Dibian based system –

root@me:~# yum install netperf iperf nuttcp nepim lmbench

** Ubuntu –

root@me:~# apt-get install  bmon bwbar bwm-ng dstat cbm etherape iftop iperf ifstat iptraf netmrg

Step 2] How to use – bmon, bwm-ng, dstat, ifstat –

root@me:~# bmon
interface: lo at me.arun.host
#   Interface                RX Rate         RX #     TX Rate         TX #
────────────────────────────────────────
me.arun.host (source: local)
0   lo                         0.00B            0       0.00B            0
1   eth0                       0.00B            0       0.00B            0
2   eth2                       0.00B            0       0.00B            0
3   vboxnet0                   0.00B            0       0.00B            0
4   pan0                       0.00B            0       0.00B            0
5   ppp0                      69.39KiB         61       7.49KiB         44

root@me:~# bwm-ng

bwm-ng v0.6 (probing every 0.500s), press ‘h’ for help
input: /proc/net/dev type: rate
\         iface                   Rx                   Tx                Total
==============================================================================
lo:           0.00 KB/s            0.00 KB/s            0.00 KB/s
eth0:           0.00 KB/s            0.00 KB/s            0.00 KB/s
eth2:           0.00 KB/s            0.00 KB/s            0.00 KB/s
ppp0:          64.39 KB/s            7.92 KB/s           72.31 KB/s
——————————————————————————
total:          64.39 KB/s            7.92 KB/s           72.31 KB/s

root@me:~# dstat
—-total-cpu-usage—- -dsk/total- -net/total- —paging– —system–
usr sys idl wai hiq siq| read  writ| recv  send|  in   out | int   csw
7   4  85   4   0   0| 281k  110k|   0     0 |   0     0 | 865  3013
8   4  88   0   0   0|   0     0 |7027B 1261B|   0     0 | 956  4505
8   5  86   0   0   0|   0     0 |  14k 1867B|   0     0 |1144  3332
9   5  86   0   1   0|   0     0 |  79k 2496B|   0     0 |1360  3366
18   8  74   0   0   0|   0     0 |  52k 6511B|   0     0 |1299  3618
8   6  85   0   1   0|   0     0 |  35k 5339B|   0     0 |1094  4231
6   4  90   0   0   0|   0     0 |   0  3164B|   0     0 | 953  2750 ^C
root@me:~#

root@me:~# ifstat
eth0                eth2                ppp0
KB/s in  KB/s out   KB/s in  KB/s out   KB/s in  KB/s out
0.00      0.00      0.00      0.00     95.73      4.31
0.00      0.00      0.00      0.00     67.93      8.17
0.00      0.00      0.00      0.00    106.77     13.70

** start “iperf” server on one host(A) and client on another host(B)- to measure Network throughput between two hosts.

* Host -A

root@me:~# iperf -s
————————————————————
Server listening on TCP port 5001
TCP window size: 85.3 KByte (default)
————————————————————
[  4] local 192.168.0.1 port 5001 connected with 192.168.0.2 port 56171
[ ID] Interval       Transfer     Bandwidth
[  4]  0.0-10.0 sec  9.11 GBytes  7.82 Gbits/sec

* Host -B
test@hostB:~$ iperf -c 192.168.0.1
————————————————————
Client connecting to 192.168.0.1, TCP port 5001
TCP window size: 49.5 KByte (default)
————————————————————
[  3] local 192.168.0.2 port 56171 connected with 192.168.0.1 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  9.11 GBytes  7.82 Gbits/sec
test@hostB:~$

root@me:~# iftop
root@me:~# cbm

Thank you,
Arun Bagul